Apparatus for the processing of frozen combestibles is disclosed in several U.S. patents, particulaly U.S. Pat. Nos. 2,409,067; 2,676,132; 2,626,133; 3,061,279, as well as in U.S. Pat. No. 4,448,114, issued May 15, 1984.
Such apparatus usually has a cup for receiving a frozen comestible, rotatable auger means, means mounting the cup and auger means for relative movement toward an away from each other, and an arm for moving the auger means into and out of the cup in a first, relatively brief operation to create a pocket in the frozen comestible for the insertion therein of flavoring material, and in a second, relatively longer operation, to mix the frozen comestible and the flavoring material and extrude the mixture from the cup. The apparatus generally sits on top of a freezer chest in which are means, usually an opening in the top of the chest, in which the cup holding the frozen comestible rests. The cup with the comestible therein is raised when necessary to bring the comestible into contact with the rotating auger means.
Although the cup and comestible therein, when seated in the opening in the top of the freezer chest, are at nearly the ambient temperature of the freezer (below 32.degree. F.), once the cup is raised out of the chest, both cup and comestible are exposed to the higher ambient temperature of the surroundings, which temperature may range from about 65.degree. to about 72.degree. F. Since the auger which comes into direct contact with the comestible, it also is at this higher temperature of about 65.degree. to 72.degree. F. This exposure to the higher ambient temperature raises the temperature of the comestible from below 32.degree. F. depending upon the ambient temperature of the surroundings.
It is well recognized that viable micro-organisms are present in all foods, including refrigerated and frozen foods. While at low temperatures microbial growth is very slow or does not occur, it is also well recognized that at higher temperatures the growth rate increases with temperature, although the optimum growth rate will vary with different microbial species. Thus, in the preparation of flavored comestibles, the higher ambient temperature of the surroundings in which the preparation is carried out may have a deleterious effect on the product. In particular, milk and milk products which are present in these comestibles are subject to spoilage at higher temperatures because of the increase in the microbial content. Fundamentals of Microbiology, Frobisher, Hindsdill et al 9th Edition, 1974, Pp 275ff and 735ff). Furthermore, the increase in the microbial content necessitates frequent cleaning, at least every two hours, of those pieces of equipment coming into contact with the product to prevent contamination of fresh material coming into contact with the equipment. This requires a halt in the production and is time consuming and costly.
The National Santitation Foundation in Ann Arbor, Mich. in its Standard No. 6 for Dispensing Freezers, published January, 1959 and revised November, 1982, has recommended that temperatures of a mixture (such as the flavored comestible being prepared according to this invention) be kept at 45.degree. F. to assure that the microbial count will be kept sufficiently low to avoid spoilage of the product.